Hollow shell



T. MURRAY ET AL HOLLOW SHELL June 16, 1942.

Filed Dec. 2, 1939 2 Sheets-Sheet 1 INVENTORS THOMAS E. MURRAY GEORGE H. PHELPS ATTORNEY.

June 16, 1942. MURRAY r 2,286,971

HOLLOW SHELL med Dec. 2, 1939 2 Sheets-Sheet 2 INVENTORS THOMAS E. MURRAY GEORGE H. PHELPS ATTORNEY.

Patented June 16, 1942 I HOLLOW snnu.

Thomas E. Murray, Brooklyn, and George H. Phelps, Floral Park, N. Y.; ,said Phelps assignor to Murray Manufacturing Corp ration, Brook-' lyn, N. Y., a corporation of New York, and said Murray assignor to Yarrum, 1nc., Brooklyn,

N. Y., a corporation ofNew .York Application December 2, 1939, Serial No. 307,194

v l4 Claims.

The invention herein disclosed relates to a hollow,streamlined shell or projectile of the type vided a shell of this type, together with a method v for making such a shell which is suitable for rapid production in quantity. This shell is as uniformly strong as that forged from a billet and the wall section varies in accordance with the desired distribution of weight necessary to position the center of gravity such that the shell is maintained, when projected, upon a true trajectory without tumbling. The shell is constructed from formed plate drawn to shape which is integrally united at the contiguous edges by a coalescense and ingraining of the metal.

In accordance with the invention, plate steel is either rolled with a formed section, or the plate is built up into a. formed section, preferably a section in which there is aportion of greater thickness along one edge. From such plate,

blanks are stamped, such that the portion of the blank which is to constitute the nose of the shell includes the portion of heavier or thicker section. This section is, of course, laid out in the first instance so that in the'finished shell, there will be the requisite wall thickness and distribution of metal in the wall of the shell. The blanks are drawn to the shape of the shell and electrically united at the engaging edges.

Several such shells, together with the plate and blanks from which they are made are illustrated in the accompanying drawings, in which:

Fig. 1 is an isometric view of 9. rolled, formed plate;

Fig. 2 is an isometric of a blank stamped from.

the plate;

Fig. 3 is an isometric viewof a drawn, shell plate; and

Fig. 6 is a longitudinal section of a shell made therefrom.

In constructing shells in accordance with this invention, the wall section of the shell is determined to provide the requisite wall thickness and distribution of metal, to obtain the proper strength and to locatethe center of gravity in the finished shell. 'Plate is rolled according to the wall section determined upon. Such a plate, having a.--form.ed section, is illustrated in Fi 1. This plate has a wall section I at one edge which is shaped such that when the plate is drawn about an axis transverse to the thickened section,

a portion la will extend axially. Another thickened portion 2 is provided adjacent the opposite edge of the plate. The two thickened portions areparallel and, therefore, readily formed in rolling the plate.

From this plate a series of blanks are stamped. One such blank isindicated bythe broken lines 3 on Fig. 1 and illustrated in Fig. 2. The blank represents the configuration obtained by developing in a plane one of two interchangeable, longitudinally divided parts which together make up the shell. This blank, cut from the plate, is subjected to drawing operations between suitable dies and caused to assume the concave form' illustrated in Fig. 3. Two such shell parts are placed in correspondingly recessed electrodes with their edges engaging. The parts are pressed together while a very high current is caused to flow between the registering edges. In this way, the metal of the parts at the registering edges is caused to embed one within the other and a coalescence and ingraining of the metal is effected.

4 The result of the foregoing operations is a hollow streamlined shell as illustrated in Fig. 4. This shell includes a thickened or heavier wall section 4 in the region of the nose which is intemally threaded to receive the fuse cap. The thickened portion 2 of the plate forms, in the shell, a wall 5 which separates a cylindrical cartridge tube 6 from the interior of the shell.

After the shell has been made as above described, the external burr formed in the welding operation is removed and the shell may then be forced through a truing die to secure the requia of uniform thickness to which there is secured,

. by welding, strips 9 and Ill. The strip 8 extends along the edge of the plate 8 and is beveled, as indicated, at its inner edge. The strip II is spaced from the strip 9 and extends parallel ,thereto. From this built-up plate a blank is stamped as heretofore described. The blank is drawn between suitable dies to form one of two interchangeable shell parts II and it. These parts are electricall united in the manner heretofore described. The shape of the nose end of the shell so formed is indicated by the broken line IS in Fig. 6 and this end of the shell is machine to the form shown in full lines. The strip IU of the twoparts form a wall it separating the cartridge tube l from the interior of the shell. The size of the strip 9 of the formed plate is, of course, determined so that in the finished shell the center of gravity of the shell will be properly located along the longitudinal axis of the shell.

In the above detailed description, the term plate is used to indicate that such shells are normally made from material that is thicker or heavier than ordinary sheet metal. It will, however, be understood that the invention is not limited to any particular gauge of metal but is suitable for all sizes of mortar shells and the gauge of material suitable for any particular size shell.

It will be obvious that various changes may be made by those skilled in the art in the steps of the method and the details of the several embodiments of the invention illustrated in the drawings and described. in detail above within the principle and scope of the invention as expressed in the appended claims.

We claim:

1. The method of making a hollow, streamlined, mortar shell having an ogival front part with a heavier wall section in the region of the forward end thereof and a tapering part at the rear of the front part which method includes the steps of forming plate with a thickened portion at one rear of the front part, which method includes rolling plate with a thickened section along one end edge, stamping two similar blanks from the rolled plate, each blank consisting of the developed, longitudinally divided one-half of the shell and having the thickened section at the edge to form the forward end of the ogival front to effect an ingraining and coalescence of the' metal at the meeting edges.

2. The method of making a hollow streamlined, mortar shell having an ogival front part with a heavier wall section in the region of the forward end thereof and a tapering part at the rear of the front part, which method includes the steps of rolling plate with a thickened portion along one edge, stamping the rolled plate to form blanks each of which constitutes a developed longitudinal sector of the shell with the thickened portion at one end edge of the blank, drawingthe blank to form a shell sector withthe thickened portion in the region of the forward edge of the sector, arranging the several sectors with the iongitudinal edges contacting and electrically uniting the contacting edges to effect an ingraining and coalescence of the metal at the edges.

3. The method of making a hollow, streamlined, mortar shell having an ogival front part with a heavier wall section in the region of the forward end thereof and a tapered part at the part of the shell, drawing the blanks to form two interchangeable shell portions, arranging the portions with their longitudinal edges in contact and electrically uniting the contacting edges of the portions to effect an ingraining and coalescence of the metal at the edges.

4. The method of making a hollow, streamlined, mortar shell having an ogival front part with a heavier wall section in the region of the forward end thereof and a tapered part at the rear of the front part, which method includes building up plate by'welding additional metal thereto to form a thicker section along one edge, stamping two similar blanks from the built-up plate, each blank constituting a development of one-half of a longitudinally divided shell and having the thicker section at the edge to form the forward end of the ogival part of the shell, drawing the blanks to form two interchangeable shell portions, arranging the drawn shell portions with the longitudinal edges contacting and elec trically uniting the contacting edges to effect an ingraining and coalescence of the metal at the edges.

5. In the manufacture of shells having a longitudinal section of varying thickness, the method which includes rolling steel to form strips, the cross section of which varies in thickness approximately as, the longitudinal thickness of the finished shell, stamping longitudinally divided semi-shell parts from the strips with the longitudinal axis of the shell parts transverse to the strips and welding the shell parts together.

6. In the manufacture of a shell having a main body portion, a cartridge container and a solid barrier between the main body portion and the container, the method which includes the steps of rolling steel plate with a comparatively heavy barrier rolled as an integral part of said plate and thinner sections on each side of the barrier, stamping semi-shell, parts from the plate arranged so that one of the thinner sections forms part of the main body of the shell and the other thinner section forms part of the cartridge container, and welding the shell parts together.

7. The method of making a hollow streamlined, mortar shell having an ogival front part with a heavier wall section in the region of the forward end thereof and a tapering part in the rear of the front part, which method includes the steps of forming blanks from plate with a heavier wall section at one end of the blanks, each blank constituting the development of a longitudinally forward end of the front part, a tapered part at the rear of the front part and a solid barrier at the end of the tapering part, which method in-' cludes forming blanks from plate with a heavier wall section at one edge of the blanks and a heavier wall section at the end of the portion to form the tapering part'of the shell, drawing the blanks to form longitudinally divided shell sectors with the heavier wall section at the edge forming the forward end of. the front part, arranging the shell sectors with their longitudinal edges in contact and electrically effecting an ingraining and coalescence of the metal at the contacting edges.

9. The method of making a hollow, streamlined mortar shell having an ogival front part with a heavier wall section in the region of the forward end of the front part, a tapered part at the rear of the front part and a solid barrier at the end of the tapering part,which method includes rolling steel strips with a thickened wall section. at one edge and a barrier strip spaced from the edge, stamping blanks from. the strip, each blank constituting the development in a plane surface of a longitudinally divided shell sector having a longitudinal wallsection corresponding to the transverse section of the strips, drawing the blanks to forward end of the front part, a tapered part at the rear of the front part anda solid barrier at the end of the tapering part, which method includes building up plate by welding thereto additional metal along one edge and a barrier strip at a point spaced from the edge, stamping blanks from the built up'plate, each blank constituting the development in a plane surface of a longitudinally divided sector of the shell and having the heavier wall section at the forward end, of the front part and the barrier at the rear end of the tapered part, drawing the blanks to form shell sectors, arranging the shell sectors with the longitudinal edges and barriersin contact and in the form of a shell, and electrically effecting an ingraining and coalescence of the metal at the contacting edges.

11. The method of making a hollow article having a barrier which method includes the steps of making steel strips with a barrier strip extending from the surface thereof, stamping blanks therefrom, each blank constituting a de-,

tuting the development in a plane surface of a longitudinally divided sector of the article and having a barrier strip extending from the surface thereof and transverse thereof, drawing the blanks to form sectors of the article, arranging the sectors with their longitudinal edges and barrier strips contacting and in the form of the article, and electrically effecting an ingraining and coalescence of the metal of the sectors at the contacting edges.

13. The method of making a hollow article having a barrier intermediate the ends thereof which method includes the steps of making steel strips with a barrier strip extending therefrom intermediate the ends thereof, stamping blanks from the strip, each blank constitutingthe development in a plane surface of a section of the article, drawing the-blanks to form sections of the article, arranging the sections with their contiguous edges including the edge of the barrier strip contacting and electrically effecting an ingraining and coalescence of the metal at the contacting edges.

14. The method of making a hollow article having a transverse barrier intermediate the ends thereof, which method includes the steps of making blanks from steel strips, each blank constituting the development in'a plane surface of a longitudinally divided sector of the article and having a barrier strip extending therefrom, transverse thereto and intermediate opposite edges thereof, drawing'the blanks to form sectors of the article, arranging the sectors with their longitudinal edges and barrier strips contacting and in the form of the article, and.- electrically effecting an ingrainingand coalescence of themetal of the sectorsat the contacting edges.

' THOMAS E. MURRAY.

GEORGE H. PHELPS. 

